Engineered Waterproof Flooring and Wall Covering Planks

ABSTRACT

Waterproof engineered floor and wall planks have a wear layer and an underlayer about an extruded dust and plastic composite core.

FIELD OF THE INVENTION

This invention relates to flooring, and particularly a new and improved waterproof flooring utilizing bamboo and plastic.

BACKGROUND OF THE INVENTION

In the flooring industry, there is a significant need for waterproof flooring that presents the appearance of a wooden floor. In particular, this flooring needs to be not only resistant to moisture, but also economical, easy to install, easy to maintain, and comfortable to walk on.

In the flooring industry, laminate flooring using fiberboard or particle board as the core layer has gained a tremendous market share. Such laminate flooring is manufactured with numerous desirable properties such as reasonable cost, stain resistance, wear resistance, easy maintenance, and fire resistance. In addition, laminate flooring is able to carry many types of printed designs, including wood grain designs.

Natural wood floors, particularly of oak and other hardwoods have been employed as flooring materials for centuries. While not as economical as laminate flooring, the appearance and comfort of wooden flooring is highly desirable. One of the most significant drawbacks to both laminate and wooden flooring is their performance when subjected to sustained exposure to moisture. In the case of wooden floors, moisture will cause swelling and warping of the flooring leading to an uneven surface and even gaps between the planks. In the case of laminate flooring, sustained exposure to moisture will frequently destabilize the integrity of the fiberboard or particle board material causing permanent and irreparable damage to the laminate boards. This leads many flooring installers to avoid the use of laminate flooring in areas that are subject to repeated or sustained moisture such as in the kitchen, bathroom, laundry room and basement areas of a house or in the commercial settings of restaurants and some retail stores.

As a result of the shortcomings of wood and laminate flooring, the choices for flooring in wet areas have traditionally been limited to ceramic tile, stone, and rubber or vinyl flooring. With ceramic tile and stone, the visual choices are limited, the cost of materials and installation is relatively high, and the resulting floors are cold in the absence of subsurface radiant heating and hard to stand on for extended periods of time. Rubber and vinyl floors can be relatively inexpensive, however, because these flooring materials are not rigid, imperfections from the subfloor transfers through the rubber or vinyl and appears on the floor surface which can be aesthetically jarring. In addition, the strength of adhesives used with rubber and vinyl floors can be compromised by moisture that can result in curling damage since the floors lack rigidity.

To address these issues, laminate flooring has been manufactured with improved moisture resistance through the selection of melamine, isocyanate or phenolic binders and through application of waterproofing materials and silicone caulking to seal voids. These steps remain inadequate however, both due to added time of installation and cost of manufacture, and because these waterproofing attempts are not 100% effective. One attempt to produce a suitable laminate plank is described in U.S. Pat. No. 7,763,345, and its related applications, where a thermoplastic material core is created and a print layer and a protective overlay are applied to the top side. The thermoplastic material core is typically a rigid polyvinylchloride compound and the core is extruded with cavities to provide cushioning. Extruded planks have a tendency to cup, however, and even with cavities, the PVC thermoplastic core is not inexpensive.

In modern construction it is also desirable to utilize green or recycled materials to minimize the environmental cost of construction. As a result, it is desirable to maximize the use of recycled or waste materials whenever possible. Therefore, a need exists for improved waterproof engineered flooring and wall covering material.

SUMMARY OF THE INVENTION

A feature of the present invention is to provide a rigid waterproof flooring or wall covering plank that includes the possibility of a wide variety of visual surface appearances, a rigid and relatively environmentally friendly core, and a cushioned backing. The engineered planks according to the invention may advantageously utilize a locking system so that the flooring can be snapped together as a floating floor, utilizing the floating floor installation method where no adhesive is required to bond the flooring planks to the subfloor. In addition, a majority of the engineered waterproof plank materials can comprise bamboo dust, wood dust or cork dust that is substantially a byproduct of other flooring manufacturing processes.

By combining the bamboo, wood or cork dust, or combination thereof, with high density polyethylene (HDPE), or polyvinylchloride (virgin, recycled, or a mixture thereof), a rigid and inert core is provided that does not absorb moisture and does not expand or contract, resulting in peaks and gaps.

BRIEF DESCRIPTION OF THE DRAWINGS

The particular features and advantages of the invention as well as other objects will become apparent from the following description taken in connection with the accompanying drawings in which:

FIG. 1 is a perspective view of an exemplary engineered waterproof flooring plank according to the invention.

FIG. 2 is an exploded sectional view of an exemplary flooring plank according to the invention.

FIGS. 3 a-d depict exemplary prior art click-lock edge configurations that may be advantageously used with various planks made according to the invention.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

In general, the present invention relates to a waterproof engineered flooring plank or wall panel. The end view of the exemplary flooring plank 10 shown in FIG. 1 shows the three principal structural components of the plank. Specifically, the top surface is a wear layer 20 that is waterproof and is selected from a number of possible materials including: tile or stone veneers; rubber; decorative plastic; decorative vinyl; linoleum; and any material (such as cork, bamboo or wood veneer) encapsulated in vinyl or resin to render the layer waterproof and wear resistant. A decorative vinyl wear layer is particularly cost and performance effective. This surface is not only resistant to moisture, but can also be provided with a static coefficient of friction (CoF) of about 0.68 according to ASTM C 1028-96, and a CoF of at least about 0.60 is desirable for most applications.

The middle section or core 30 of the engineered plank 10 is formed from between about 55 to 80%, and preferably about 70% of bamboo dust, wood dust, cork dust or a mixture thereof. The remaining 20 to 40% consists of high density polyethylene (HDPE) or alternatively, virgin or recycled PVC or a combination of such PVCs, and up to about 10% chemical additives such as anti-UV agents, anti-oxidation agents, stabilizers, colorants, anti-fungus agents, coupling agents, reinforcing agents, and lubricants. Calcium carbonate may also be added as a filler. After blending and melting the dust and HDPE, the composite material is extruded to desired dimension. This type of HDPE and dust composite has previously been manufactured primarily for use as outdoor decks, railings and fencings, but heretofore has not been prepared in a fashion that was sufficiently visually appealing for residential or commercial flooring. Instead, these wood-plastic or bamboo-plastic composites have been colored according to a limited color pallet and promoted for exterior use. When used in the present invention, some additives, such as anti-UV agents, are not needed. Also, heretofore, cork dust has not been a principal ingredient of the plastic composites. Whereas generally the addition of greater amounts of wood or bamboo dust provided greater rigidity to the resulting planks, cork dust retains some resilience even in the plastic mixture. The core 30 can be solid, or can be provided with channels if desired, particularly in relatively thick embodiments.

The underlayment layer 40 is attached to the dust and plastic core 30 and is also made of waterproof or water resistant material such as cork, rubber, foam or waterproof balancing paper.

The plank 10 also has a grooved end 50 with profile 51 and channel 52 that matches with protruding end 60 having profile 61 and protrusion 62. The particular profiles are made according to a preferred design to allow the panels to be quickly locked together, typically without the use of adhesive. However, if desired, an adhesive may be applied to the profiles therefore joining planks together to create a more permanent bonding of adjacent planks. The matching profiles may be of the click-lock variety depicted in FIGS. 3 a-d or a more traditional tongue and groove construction that generally requires the use of an adhesive.

FIG. 2 is an exploded view of the various layers that may be included in a plank or wall panel of the invention. The top layer 21 is an optional protective overlay or cover layer that is most desirable when the wear layer 20 is not particularly durable. Preferred top layer characteristics include transparency, hardness and scratch resistance. Exemplary materials for a top layer 21 include melamine resin with aluminum oxide and polyurethane. Wear layer 20 is less likely to benefit from a top layer 21 when comprised of a durable material such as tile or stone, or when the wear layer 20 already includes a protective hardener such as is the case with resin or vinyl encapsulated bamboo, wood or cork.

A bonding layer 22 joins the wear layer 20 to the core 30 and is typically a water resistant adhesive. A preferred adhesive type is a hot melt adhesive that can be applied during the manufacture of the engineered flooring or wall covering, at temperatures over 200° F., and more commonly over 250° F., and is therefore not suitable for convenient use at a residence or commercial establishment when flooring is being installed. The hot melt adhesive should be water resistant or nearly impervious to significant and prolonged exposure to moisture.

Another bonding layer 41 joins the underlayment layer 40 to the core 30. As with the first bonding layer 22, this second bonding layer 41 is also preferably a hot melt adhesive that is nearly impervious to moisture. The underlayment layer 40 is selected from a variety of possible materials depending upon the price point and functionality of the flooring or wall covering planks.

Planks according to the present invention are advantageously provided with click-lock edge systems, such as the protrusion 62 that co-operates with channel 52 and edge profiles 51, 61. Pervan, U.S. Pat. No. 6,023,907 and Morian, U.S. Pat. No. 6,006,486 disclose two of the leading edge fastening systems. FIGS. 3 a-d show a variety of other click-lock edges. The system in FIG. 3 a can be angled and snapped, FIG. 3 b shows a snap joint, FIG. 3 c can be angled and snapped but generally has less joining strength than the system of FIG. 3 a. FIG. 3 d also shows lock and fold panels with the first panel having a channel on the right edge being installed and the second panel being angled so that its protrusion enters the channel and the top edges of the two panels contact, and then rotating the second panel downward until the profiles are locked. When using click-lock edges, it is relatively straightforward to install floating flooring without adhesives. The particular edge system that is preferred for a particular plank may vary depending upon the dimensions and rigidity of the plank. It will also be understood that planks and panels according to the present invention can be installed using adhesives, and the adhesives can be applied to join the edges of the planks or to attach the planks to the subfloor or wall, or both.

The planks and panels according to the invention are generally rectangular having a thickness of up to about one inch and a width of between about 2 and 12 inches. In general, flooring planks will have a greater thickness than wall covering planks or panels. The use of recycled wood, cork or bamboo dust contributes to sustainability through the responsible management of resources, and provided bamboo, cork or sustainably harvested wood is used, results in an environmentally friendly building material.

The planks and panels manufactured according to the invention are nearly impervious to swelling and have great dimensional stability with variations due to moisture of less than 0.01%. The products can also be manufactured to tolerances of less than 0.25 mm of length, width and straightness, and many suitable wear layers provide colorfast and cleanable surfaces.

Numerous alterations of the structure herein disclosed will suggest themselves to those skilled in the art. However, it is to be understood that the present disclosure relates to the preferred embodiment of the invention which is for purposes of illustration only and not to be construed as a limitation of the invention. All such modifications which do not depart from the spirit of the invention are intended to be included within the scope of the appended claims. 

1. An engineered waterproof plank comprising: (a) a wear layer adhered to a top surface of a waterproof core; (b) a first waterproof adhesive layer bonding the wear layer to the top surface of the waterproof core; (c) the waterproof core comprising an extruded dust and plastic composite; (d) the plank having a first edge with a groove extending laterally into the waterproof core and a second opposite edge with a lateral protrusion from the waterproof core, wherein the groove and protrusion have profiles shaped to form a click-lock edge fastening system.
 2. The plank of claim 1 wherein the wear layer is selected from the group consisting of tile veneer, stone veneer, rubber, decorative plastic, linoleum and decorative vinyl.
 3. The plank of claim 1 further comprising an underlayer selected from the group consisting of cork, rubber, foam and waterproof balance paper.
 4. The plank of claim 1 further comprising a cover layer over the wear layer.
 5. (canceled)
 6. (canceled)
 7. The plank of claim 1 wherein the wear layer is selected from the group consisting of cork, bamboo and wood veneer, said wear layer encapsulated in resin to render the wear layer waterproof and wear resistant.
 8. The plank of claim 1 further comprising a cover layer over the wear layer, said cover layer selected from the group consisting of melamine resin with aluminum oxide and polyurethane.
 9. The plank of claim 1 wherein exposure to moisture results in swelling of plank dimensions by less than 0.01%.
 10. The plank of claim 1 wherein the first waterproof adhesive layer further comprises a hot melt adhesive.
 11. The plank of claim 3 further comprising a second waterproof adhesive layer bonding the underlayer to a bottom surface of the waterproof core.
 12. The plank of claim 21 wherein the waterproof core further comprises less than 10% of additives selected from the group consisting of anti-oxidation agents, stabilizers, colorants, anti-fungus agents, coupling agents, reinforcing agents and lubricants.
 13. The plank of claim 1 wherein the waterproof core further comprises calcium carbonate filler.
 14. An engineered rectangular waterproof plank comprising: (a) a wear layer of decorative vinyl adhered to a top surface of a waterproof core by a hot melt adhesive; (b) a cover layer over the wear layer, said cover layer selected from the group consisting of melamine resin with aluminum oxide and polyurethane; (c) an underlayer selected from the group consisting of cork, rubber and foam, adhered to a bottom surface of the waterproof core by a hot melt adhesive; (d) the waterproof core comprising an extruded dust and plastic composite, said waterproof core having substantially planar top and bottom surfaces separated by a thickness defining a first edge along a first side and a second edge along an opposite second side, and third and fourth edges along opposite third and fourth sides, wherein the first edge has a groove extending laterally into the waterproof core and the second opposite edge has a lateral protrusion from the waterproof core, the groove and protrusion having profiles shaped to form a click-lock edge fastening system.
 15. (canceled)
 16. The plank of claim 14 wherein the static coefficient of friction of the plank is at least 0.60 as measured according to ASTM C 1028-96.
 17. The plank of claim 22 wherein the waterproof core further comprises less than 10% of additives selected from the group consisting of anti-oxidation agents, stabilizers, colorants, anti-fungus agents, coupling agents, reinforcing agents and lubricants.
 18. The plank of claim 22 wherein the waterproof core further comprises calcium carbonate filler.
 19. The plank of claim 14 wherein exposure to moisture results in swelling of plank dimensions by less than 0.01%.
 20. An engineered rectangular waterproof plank comprising: (a) a wear layer selected from the group consisting of cork, bamboo and wood veneer, said wear layer encapsulated in resin, and said wear layer adhered to a top surface of a waterproof core by a hot melt adhesive; (b) an underlayer selected from the group consisting of cork, rubber and foam, said underlayer adhered to a bottom surface of the waterproof core by a hot melt adhesive; (c) the waterproof core comprising: (i) at least about 55% of dust selected from the group consisting of wood, bamboo, cork and a combination of two or more of wood, bamboo and cork; (ii) at least about 20% of high-density polyethylene; and (iii) calcium carbonate filler; (d) said waterproof core having substantially planar top and bottom surfaces separated by a thickness defining an edge along opposite first and second sides, and along opposite third and fourth sides, wherein a groove extends laterally into the waterproof core along the first edge and a lateral protrusion extends from the opposite second edge of the waterproof core, the groove and protrusion comprising a click-lock edge fastening system.
 21. The plank of claim 1 wherein the waterproof core comprises: (i) at least about 55% of dust selected from the group consisting of wood, bamboo, cork and a combination of two or more of wood, bamboo and cork; and (ii) at least about 20% of plastic selected from the group consisting of high-density polyethylene and polyvinyl chloride.
 22. The plank of claim 14 wherein the waterproof core comprises: (i) at least about 55% of dust selected from the group consisting of wood, bamboo, cork and a combination of two or more of wood, bamboo and cork; and (ii) at least about 20% of plastic selected from the group of high-density polyethylene and polyvinyl chloride. 